


Underlying Cause

by CoLaLu24



Category: Sherlock (TV)
Genre: Butt Plugs, Explicit Sexual Content, I just needed some kind of initial situation, Light Dom/sub, M/M, Naughty Sherlock, Prostate Stimulation, So light it barely counts, porn with almost no plot
Language: English
Status: Completed
Published: 2017-10-14
Updated: 2017-10-14
Packaged: 2019-01-17 05:00:46
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 2,783
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/12357993
Author URL: https://archiveofourown.org/users/CoLaLu24/pseuds/CoLaLu24
Summary: "'As I have already said, John, I'm absolutely fine,' Sherlock murmured and locked his piercing blue eyes with his friend’s.'The expressions of pain and pleasure can look quite similar, can’t they?'"





	Underlying Cause

**Author's Note:**

> The idea for this story came to my mind some days ago and I just needed to write a short fic about it :)  
> As the tags might show, this story doesn’t contain that much plot, but actually this wasn’t my intention, as I would say that the focus is on something else ;)
> 
> As always, please note that English isn’t my first language, so I apologise for any mistakes!  
> Anyway, I hope you enjoy reading it, as much as I enjoyed writing it ;)

 

 

"The time of death is approximately around 11 p.m., so she has been dead for quite a while now," Lestrade explained and gestured to the body of the stabbed woman that was lying on the floor in the middle of the room.

"According to Anderson, the victim did…"

 

"Yes, thank you for your inputs, Lestrade. But I think I can easily manage without them now," Sherlock interrupted him and harshly indicated him that he should keep his assumptions to himself.

"Sherlock!" John rebuked him and wondered, why his flatmate was even more twitchy and irritated than usual.

 

But Sherlock just grunted something incomprehensible in response and kneeled down next to the woman. He flexed his back, the fabric of his coat tightening along his spine and arms and exhaled deeply. - He couldn't keep still for one second.

 

John watched the constant shifting of the younger’s hips with irritation and started to furrow his brow. Something was definitely strange…

When Sherlock bent over the body and subconsciously contorted his face for split seconds, the wrinkles on John’s forehead became even deeper.

 

"Sherlock, are you all right? Is there something wrong with your back?" he finally dared to ask and tilted his head in expectation of an explanation for Sherlock’s unusual behaviour.

 

The consulting detective’s piercing blue eyes locked with John’s, his dark pupils swallowing him like black holes.

"I am absolutely fine, John," he replied smoothly, before turning his gaze away to examine the victim’s hands.

 

"It’s obvious that the husband is the murderer," Sherlock finally said and with an almost inaudible – but not to John - grunt got up from his kneeling position.

 

"And it’s obvious because…?" Lestrade asked, the usual confused look when Sherlock solved a case after mere seconds, covering his face.

 

"You can see the outline of a ring on her left ring finger. Combined with the way she’s dressed she must have wanted to meet her affair. But her husband pre-empted their next secret meeting," Sherlock explained and buried his hands in the pockets of his coat. John could see him clenching and unclenching his fingers underneath the thick fabric, again unable to hold still for even the shortest amount of time.

 

"Um… Okay thank you, we’ll follow this up," the grey-haired DI said and wrote something on a piece of paper.

 

"Well, then I think we’re done here, right?" Sherlock exclaimed and turned around to leave the crime scene, his coat fluttering behind him.

 

 

<> 

 

 

John sat in his armchair in the living room of 221B and turned the page of his book. The black letters danced in front of his eyes, but he just couldn't focus on them.

Sherlock had rushed to his room as soon as they had been back at their flat and hadn’t left it since then. - And John still wondered what was wrong with his younger flatmate. Had he contorted his face in pain? Or was it just something he shouldn't pay that much attention to?

 

John snapped the book shut and placed it on the table next to his armchair with a mild thump. He pinched the bridge of his nose between his fingers, _again_ remembering Sherlock’s face a few hours ago. No, he wouldn’t come to rest, until he’d found out the reasons for all of that.

 

But when John finally stood in front of the closed door to Sherlock’s bedroom, he hesitated nevertheless. Shouldn't he just leave Sherlock alone? Letting him deal with whatever crisis he had? However instead the decision was made for him, when he could hear a muffled grunt echoing through the wooden door.

 

"Sherlock?" he asked, but didn’t wait for a response, before he turned the doorknob and let the door swing open.

The inside of Sherlock’s room was revealed and it was as if John’s blood circulation stopped, as if every little muscle in his body tensed. He needed to grab the doorframe to get hold, to be able to realise the scenario in front of him.

 

Fading sunlight flooded through the windows and outlined the figure of Sherlock on his bed. He kneeled in the middle of the mattress, one hand placed flat in front of him, attempting to steady himself. His upper body was bent forward, his skin straining over his spine, his muscles flexing with every move.

_He was completely naked_. His legs were spread wide, his toes curling into the silken fabric of the sheets.

And _fuck_ \- his erected cock stood upright from his body, drops of precome glistening on the tip, slowly running down the heated flesh. Sherlock’s chin rested on his chest and strands of his brown curls were clinging to his forehead that was covered by a thin layer of sweat.

 

His right arm led between his legs, where his hand was closed around the black base of a butt plug. He steadily worked the upper part of the toy in and out of his arse, stretching his tight hole in an agonisingly slow rhythm.

And the plug seemed to be so… _huge_. The size of it wasn’t comparable to the smaller ones that lay next to Sherlock on the bed, the ones John barely noticed, as his attention was caught by everything else.

 

But nevertheless did John take all of this in in split seconds, feeling overwhelmed and shocked at the same time. - But the betraying twitch of his cock showed him, which impression really dominated.

 

Sherlock raised his head, his eyelids fluttering opened and his blown-wide pupils met with John’s.

"As I've already said, I am absolutely fine, John," he murmured, his voice hoarse and deep.

 

John didn’t know what to say, didn’t know what to do. They only thing he knew for sure was that he should have thrown the door shut as soon as he had seen Sherlock on his bed. But fuck he hadn’t. He hadn't want to.

 

His eyes took in the sight in front of him once more. His gaze followed the soft trail of dark hair that covered Sherlock’s porcelain chest, before he let it slide further down, until it rested on Sherlock’s hand and the base of the plug that was clutched tightly by his long fingers.

 

The younger Holmes slightly tilted his head, the blue of his eyes shining through his dark lashes, but he made no move to throw John out of his room.

Quite the contrary, he slowly started to lower his hips to push the plug deeper and deeper inside his body, his eyes never leaving John’s.

 

Sherlock's parted lips escaped small gasps and moans, when the widest part of the toy breached his hole until it was finally completely buried inside him.

 

"The expressions of pain and pleasure can look quite similar, can’t they?" Sherlock asked and breathed heavily.

_Fuck. Sherlock had worn a butt plug at the crime scene. Fuck._ The mere thought that Sherlock’s behaviour a few hours ago had been the result of the constant stretching and stimulating of a sex toy, made John’s cock harden in his pants. The imagination was just so utterly hot, so utterly _arousing_.

 

"I wouldn't have expected that you would indulge in something like that," John said with a teasing smirk and made a few steps towards Sherlock.

"Maybe, I changed my mind. Maybe I wanted to try something new and unfamiliar," the younger Holmes purred and licked over his plush lips, leaving them glistening in the light.

"But what about you, John?" Sherlock asked, his baritone voice soft and smooth like melting chocolate.

"Do you just plan to stand there and watch me fucking this plug until I come all over my bed?"

 

"Oh, such filthy words, Sherlock," John murmured and crossed the remaining space that separated him from Sherlock’s bed. He placed on knee on the mattress, between his and Sherlock’s chest were now only mere centimetres left. He was so close that he could hear Sherlock’s fluttering breaths, could almost feel the fast and aroused beating of his heart.

 

With one swift movement John threw himself on Sherlock and pinned him down on the bed, his cloth-covered body pressed against his friend’s.

"Although what you just suggested sounds quite enticing, I prefer to do something else instead," John whispered, his breath ghosting over Sherlock’s ear, letting a shiver running down his spine.

 

"I don’t just want to watch you fuck this toy with your gorgeous arse, as you stated it," he continued and leaned back a little bit, using one arm to steady himself. He lifted his other hand and brushed a brown curl out of Sherlock's forehead, twirling the moistened hair around his finger.

"I would rather fuck you with this filthy toy," John said while trailing his fingertips along Sherlock’s jawline, over his smooth chest, along his hipbone until he finally closed his hand around the base of the plug.

 

The material felt warm and soft, perfectly fitting in the curve of his hand. John steadied his grip and slowly pulled the toy out a little bit, changing the angle so that the rounded tip was pressed against Sherlock’s prostate.

"Oh God," the younger man growled and John could feel his bare cock twitching against his stomach.

 

"Yes," John breathed heavily and pushed the plug in with almost brutal force, aiming for the bundle of nerves again.

"Keep your hands where they are. I want to hear you moan, to hear you beg me to let you come," he demanded, the desire to see Sherlock like this stronger than ever before.

 

Precome dripped out of Sherlock’s cock, the milky fluid soaking into the fabric of John’s shirt, unmistakably marking it, but in this moment John couldn't have cared less. He was far too gone. Too lost in the sounds Sherlock made, in the feeling of his naked body so close to his own.

 

Sherlock’s previously applied lube leaked out around the base of the plug, running warm and sticky over John’s hand. The doctor shifted on the mattress, so that he could see the toy sliding in and out of Sherlock’s loosened hole. Every time he pulled it out of Sherlock, the muscles of his arse clenched around the plug, as if his body wouldn't want to release it, before he’d finally felt the orgasm he craved for.

 

"Please, John," Sherlock gasped in agony. White patches seemed to dance in front of his eyes and sharp sparks of electricity flooded through his bloodstream at the constant, relentless stimulation of his prostate.

 

"Oh, Sherlock, I thought that you would have lasted at least a little bit longer," John teased him and ruthlessly continued the thrusting with the plug.

Thick drops of precome ran along Sherlock’s cock, but he couldn't come like this, he needed to touch himself. It was so unbearable and yet so incredibly pleasurable.

 

The younger man threw his head back into the pillow, his eyes shut in agony, in the desperate longing to come. His nails were dug into the mattress, scraping over the sheets, but he hadn’t touched his cock yet.

_"He can obey, when he wants to,"_ John thought and smirked.

 

"What was it like to walk around the crime scene with a plug shoved in your arse?" John growled, while continuing his thrusting moves.

"Which one did you use? This one?" he asked and lifted a small grey plug from the mattress.

"Or was it a bigger one, so that you could feel your hole being stretched wide and mercilessly?"

 

"God, yes… it was… fuck…so," Sherlock muttered incoherently, the pleasure he felt making him unable to form a complete sentence anymore.

 

"You must want to come so frantically. To finally give in to an orgasm that provides you the relief you want," John murmured and watched Sherlock’s hands twitch on the mattress next to him. A wordless affirmation.

 

"God, how were you even able to fit something like _this_ inside you?" John asked and pulled on the base of the plug, carefully removing the toy centimetre after centimetre.

 

"Practice, John," Sherlock gasped and inhaled sharply, when John let the last centimetres of the plug slide out of his arse.

 

"I guess I shouldn’t underestimate you in one way or another," John replied, letting his gaze roam over the glistening surface of the plug, a hint of admiration readable in his eyes.

 

Sherlock’s hole still gaped wide and empty, wide and _invitingly_ and John lightly brushed his fingers over the ring of muscles, feeling it twitch under his touch. He gathered some of the lube that ran down Sherlock’s skin and spread it on his own hand, slicking up his fingers with fast and impatient moves.

"But doesn’t this feel better?" John purred and buried his fore and middle finger inside Sherlock’s arse with one deep thrust.

 

The younger man just hissed in response, when the lifeless material was finally replaced by John’s fingers. But the doctor escaped equal sounds, when he was enveloped by the heat and tightness of Sherlock’s body.

 

John started to bend his fingers, feeling the puckered hole clenching and widening around them, while he searched for the bundle of nerves inside Sherlock’s body. He knew that he had found it, when his fingertips brushed over a little nub and a suppressed scream joined the ragged breathing that was already echoing in Sherlock’s bedroom.

 

"Now, Sherlock. I want to see you stroking your cock, while I fuck your arse with my hand," John demanded and Sherlock’s fingers almost immediately closed around the base of his throbbing erection. He moved his hand up and down, letting the heated flesh slide through the tight ring of his fingers.

 

When John’s fingers relentlessly brushed over his prostate, Sherlock couldn’t bear the feeling any longer and was finally pushed over the edge. He gave his cock one last fierce stroke, until thick stripes of come spilled all over his hand and stomach. His whole body trembled in pleasure, his hear beat fast and erratically in the finally found release after the almost unbearable stimulation.

 

When Sherlock was overwhelmed by his orgasm, when he fell apart under John’s touch, the blonde couldn't ignore the straining of his own cock any longer and squeezed it through the rough fabric of his jeans. He rubbed his palm over the bulge and moaned when suddenly a wet and heated hand was placed on his own. Sherlock pressed their combined hands against John's crotch, so hard and forceful that John’s pulse vibrated in his dick.

 

John’s eyes met Sherlock’s. The blue ring of his iris was barely visible anymore, almost covered by the blackness of his dilated pupils. Sherlock's tongue appeared between his lips and he brought his semen-covered hand up to his mouth. Not breaking the eye contact for one second, he licked over the white drops that clung to his skin, sucking them off with almost obscene flicks of his tongue.

 

John's hips bucked up involuntarily at the sight, leaning in the form of Sherlock’s hand, craving for the other’s touch.

Slowly, _teasingly_ Sherlock opened up John’s jeans and slid them down a little bit, so that his black briefs were exposed. A wet spot covered their tented front; a darker shade on the plain fabric, an unmistakable sign of John’s arousal. Sherlock looked at it with hooded eyes and brushed his fingers over it, rubbing the wetness into John’s skin.

 

"Sher-lock," John groaned and shifted his hips. "Don’t – don’t tease me," he warned, but was already far too lost in the feeling of Sherlock’s hand on his crotch that it was a serious threat.

 

"How could I dare, John?" Sherlock smirked and finally lifted the waistband of John’s boxers to close his hand around the shaft of his throbbing cock.

John’s breathing hitched for a second, to delicious the feeling of Sherlock’s long fingers on his cock, skin against skin.

 

Sherlock started to move his hand up and down John’s length, letting his hard erection slide through his still wet fingers and John threw his head back in agony.

He parted his lips, ragged breaths escaping his mouth, shallow and fast.

 

When Sherlock rubbed his thumb over the slit at the head of John's cock, spreading the drops of precome, the doctor couldn't keep him self from groaning low and deep. His balls tightened, drawing up to his body and he shuddered and gasped when warm spurts of semen pulsed inside his briefs, gushing all over Sherlock’s hand, sticking the material of his shorts against his skin.

 

"Fuck," John sighed and indulged in the aftershocks of his orgasm. "That was…"

 

"Yes, John," Sherlock murmured and stroked John’s slowly softening cock, his hand still buried in his pants.

"Yes, it was not was you’d expected. One way and another."


End file.
